1. so the first one i'm trying to remember is of the uke who has a crush on the seme, while the seme has a thing for BL and collects it. the uke ends up pretending he's all into collecting it as well, but later on the seme realizes he really likes the uke. there was also a part where they went to a convention and the uke assumed the seme had a girlfriend during.

2. the second one is where the seme collects anime figurines and the uke likes him; I don't remember much, but later on the seme ends up getting hooked on doing it with the uke and I think the uke ends up getting upset with him over it? - FOUND IT; it was the second chapter in Soshite Boku wa Koi wo Suru

Mashita no Fudanshi-kun by Kuroiwa Chihaya?