>>279683974
How new are you to the series? Araragi constantly "disavows" things and then proceeds to do them anyway. The boyfriends were also an obvious tactic by the sisters to try to make Araragi feel insecure. Some even theorize that the boyfriends represent the sisters themselves due to kanji or something. They could've been hinting that they'll just spend even more time together if they can't get Koyomi. It is already directly implied that they only really started sleeping naked together and stuff when Koyomi started distancing himself from everyone.

>>279580589
Araragi when casually referring to him. Koyomi when his sisters are in the sentence by name.