So I am guessing 5 or 6 centimetres. I encountered a micro penis in the wild, years back, when I was dating after being a single mum for a few years. It was actually horrible and I found it completely off putting and honestly kind of repulsive. Like a white worm.
Of course I didn't say that to him, we just did not go on to have sex as it really wasn't possible, we talked for a while, fell asleep and the following week I just ended the relationship as kindly and nicely as I could. Don't really want to give more detail about it than that, but it sticks out as a really unpleasant experience that I wish he could have found the courage to warn me about. Because I would then have said no and spared us both the embarrassment and bad memory.
He didn't tell me. He asked me a couple of times if the reason I was dating an older man (he was ten years older than me I was mid 40s at the time) was because sex didn't bother me. I was confused and said no I was happy to have sex. I realised later he was hoping I'd say yes, I am just looking for companionship.
Looking back, he was reluctant to get to the sex stage, despite claiming otherwise. I made a comment about how big his feet were once and he said something like "well, sometimes men with big feet have tiny dicks!" I thought he was joking.
He was not joking.
I did and do feel sympathy for him and it would have been fine if I had not also been hoping for standard, penetrative sex and if he'd let me know. It's not odd, unkind or any other pejorative to expect a man to have a functional penis within a standard range when entering into a sexual relationship, and yes it was incumbent on him to let me know.
But I do actually get why he didn't, and don't hold that against him.
I just will absolutely not have anybody try to hold my natural preference against me either. Absolutely not.
People are allowed to want whatever they want. If my husband's penis suddenly shrunk to that of a white worm I'd still love him, stay with him, and would never tell anyone or do anything to make him feel less about it, better for worse, sickness and in health and all that.
But a boyfriend is quite different. The reality is, you probably won't know until you see it and are in bed with him. I wouldn't pursue the relationship, but that's just me, maybe you'll be different.