Enough with all the definite "no" responses above. I know people mean well but you have no idea how disheartening and unhelpful it is to be told this from people who have no idea what the inside of someone else's j-pouch looks like. I would ask that people stop responding like this. Everyone's j-pouch is different, therefore there is no universal answer for any question relating to our pouches.
Kharma, I am a 27 year old gay man, and like you had my j-pouch created when I was 18, before I was sexually active.
Do not be embarassed about asking the question - it doesn't matter what your orientation is, and it doesn't matter if you don't know, but the only way to be more empowered is with knowledge, so you've made the right step by asking the question.
Having said that, the only person who can answer your question the most accurately is your surgeon and medical team. Only they know what the inside of your pouch looks like. They may say yes, they may so no.
In my case I returned to my surgeon a few years after my op with the question. He was helpful and unprejudiced (as all should be, but unfortunately not all will be), and gave me the answer, which in my case was yes: it would be okay but tread slowly and carefully.
I'd encourage you to speak to your surgeon and medical team. Don't feel embarrased - it's the only way to get the best answer. If the answer is yes, congratulations, and be careful, don't go crazy. If it's a no, then that's okay too. Queer culture may make you believe it's all about penetration, but it really isn't, and finding someone you love will help you with that journey.
DM with any questions.