Yes, medically speaking some people are tighter in the arse than others.
Most (not all) humans are rather weak in the anus - meaning their sphincter muscles are a bit atrophied. This leads to them having more issues such as herniated muscles (hemorrhoids) and even prolapse.
IF a person is in general good shape and do lots of straining - not in the toilet, but elsewhere, such as they do a lot of lifting and bring their abdominal muscles to bear, then tend to be a bit of a tight ass.
I have seen a video where a man was doing a squat/stand up lift of heavy weights, he was a body builder, and attempted to lift more than he had before. His ass exploded from the strain of lifting, he prolapsed - badly.
If you care to take a peek you can find it here:
http://forum.bodybuilding.com/showthread...324&page=1 Mind it is
very graphic and disturbing, and if you are not into medical things this may give you nightmares for life.
Why do I delve into the realm of anal prolapse? To give you some understanding on how the body works and to demonstrate that other activities other than what you do in the toilet can lead to a stronger or weaker anus and sphincter muscles.
So, if you are a laborer, say construction, doing lots of lifting, squatting and the like, it is highly probable that your anus is a bit tighter than the office boy who's day consists of pushing papers and answering phones. If you work out, lift weights, exercise and strain the abdomen (correctly) changes are you have worked the sphincter muscles and attending muscles without even knowing you have to the point where yes, you are tighter.
Like it or not (Lord know the anti-gay crowd loves to focus on this little factoid) the Anus is not designed to have things go up it. It is designed to have things come out and if anything to work at keeping things from going up. Yes it can be 'trained' to accept, yes it can be 'trained' to relax. The sphincter muscles are muscles, and like most other muscles can be stretched, pulled, and over time trained to relax and tighten more.
Understand that being a bottom is not just having a desire to have your prostate massaged. There is a lot of emotional response to having a man inside of you, and not just sexual pleasure. There is a definite mindset and willingness to be a bottom that also includes a huge helping of trust.
Other minor emotional/mental things play a role, such as the idea that you cease to be a man if you allow another man to treat you like 'a woman'. That can have a huge impact on how relaxed you are. You may not be aware that 'manliness' is playing a roll in your stress levels, but it is there, lurking under a slew of other emotions at the time. Society, if it has done its job, has worked real hard to define and give you concrete beliefs on what its like to be a certain gender.
From the moment we are born we are taught that a penis between the legs is blue (not the penis, but we dress in blue, paint the nursery blue, etc). Wears pants (Ma dressed you in sailor suits didn't she?) You got the sports equipment (Dad didn't bring you a doll now did he?) As you got older the gender-roles were made very clear to you in millions of tiny ways, from 'Big Boys don't dry' to "Boys don't ever, never, ever, ever play with easy bake ovens and dolls."
You are product of all of that, and it will affect your emotional status when laying in bed, even by yourself 'experimenting' with stuff.
You say you are a top. There is a certain mentality that exists when you are a top. This goes well beyond the sexual pleasure of sticking your dick somewhere. It also includes your feelings of dominance, masculinity, etc. A lot of tops are more protective, more willing to be the provider, more attuned to being the leader in and out of bed. They tend to be the one who does the comforting, its your shoulder that needs a head resting on it, the bottom's head tends to need a shoulder to rest against.
Top/Bottom roles are not make believe and they are not just simple sex acts. They are complex emotional expressions and responses.
These are very complex and deep seated emotions, perhaps we are even hardwired for these things via genetics and hormones and the like.
Your 'issue' with accepting an object up the butt may be more complex than just being able to relax the anus enough, you may actually be hard wired to be merely a top.
Its OK to be
just a top, don't beat yourself up over about it. :tongue: