Of course it is possible to not bleed when you lose your virginity. Some people do bleed, but that's not the norm. Why would it be? Sex is something your body wants to do. It's your body's purpose. Your body does not want it to be awful, painful, and bloody. The whole "sex should be painful and bloody your first time" thing is a myth.
Also, being tight or loose does not mean what he thinks it means. The vagina can seem tighter or looser depending on how in the mood the woman is. The vagina doubles in size when the woman is in the mood.
Usually, men who are circumcised do lose a bit of the sensitivity that uncircumcised men have.
Honestly, your boyfriend sounds like he needs some serious sex education. Personally, I am not sure if I would want to be having sex with someone who not only does not know what they are talking about, but also makes accusations of cheating. It sounds there are serious trust issues, and he's filling your head with absolute garbage when it comes to sex and your own anatomy!
Here are some sites that you can look at if you want to know more about sex and anatomy:
http://www.coolnurse.com/sex_faqs_index.ht
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http://www.coolnurse.com/hymen.htm