UC and boyfriend

[TheSpiritofDarkandLonelyWater]

I am on UC and have a boyfriend of over 2 years. We do not live together. We have separate households and bills etc.
But he stays at mine on the weekend. We eat out together and he pays. Sometimes we cook a meal at my house and we split the cost of the shopping.
I am a bit shook up from some other posts on here that said that I should not be on benefits if I am seeing him and he takes me out for a meal and stays over sometimes.
I can not find anything online about the rules about this.

Do I need to tell job centre about him? Am I committing fraud?

I'm not on UC anymore but I thought it was down to if you rent and pay bills at separate addresses. I stay at DPs twice a week, but I don't contribute to the running of the house, maybe the odd takeaway but we take that in turns