it shouldnt for you, but it may be a litle painful for your girlfriend. but be sure to use protection.

but you are thirteen and you are going to have sex??? doesnt sound like you are ready

It is an ironic twist that Mother Nature plays on us in that we become physically ready for sex before being mentally and emotionally ready. A thirteen year old girl is not really ready for sex for both reasons. Her body is not yet fully developed inside and her brain has a few more years to go in order to be emotionally ready for this. You may be able to enjoy orgasms; however, I can assure you that at your stage of life you are not yet prepared to handle sex. This is not a put down of you or anyone else your age, just a statement that in your arc of life, this is where you are and both of you have a lot more maturity to accomplish before being ready.

Do not be in such a rush. Be a child for a while longer before undertaking adult behavior. You have the whole rest of your life to be an adult and to deal with all that that entails, in the meantime, be a kid until your brain, intellect and emotional maturity catch up.

i knew this would happen. god, i get so damn miffed when people tell kids when they should be ready. they both say they're ready, so they are ready. mental maturity doesn't come into it. not as far as nature is concerned. and they can have sex and still be kids, but lets face it if they were living in the wild like our ancestors they wouldn't be asked to be kids. growing up should never be discouraged. it's a romantic notion. kids are mollycoddled for such an extended period. i lost my virginity at 14 and i was ready sooner. i don't regret it one bit. i was ready. i was very ready. he was 21 and i do not consider that i was raped either. it was my choice. i could have said no and that would have been that. and i don't want to hear people bring up words like peadophilia or rape or that i'm sick and immoral or anything negative. there was nothing negative from my experience nor for many many others. it's all about your hang-ups. not everyone elses.
now for some helpful advice, i hope. because no matter how discouraging people are here you may still go ahead and not have the information you need.
earny, please for the love of god, USE A COMDOM. and know how to use it. a girl can get preganant at 13 and that's a big burden. and yes, it will hurt for her so if you go ahead take it slow and tell her if she doesn't know yet that she may experience pain for the first few times, but that doesn't mean anything is wrong. i found sex a little painful at first. sometimes i still do depending on the size of the penis. but if she says stop, please do. one must always respect the other's body and understand their request. she'll need manual stimulation first and if she's not naturally lubricated enough you might want to buy some. do not go in if she's not lubricated. painful.
and both of you should take the oportunity to look around this site thoroughly. it's a gold mine of useful mature advice that i wish i had access to when i was a kid. you're so lucky with the amount of advice available to you.
take care.

i aint gonna tell u that u aint ready for sex or anythin but all i would say is make sure to use a condom, and for ur sake... dont get "fukin" caught, i dunno where ur from but am pretty sure the legal age is older than 13, and gettin charged for sleepin wi an underaged gal (doesnt matter if ur underage too the law doesnt look at that as bein ok) will not work well for u in the long term.

anyway have fun... be it wi sex or not :cool: