my son is suddenly starting to bite my nipple. is that a sign that he's teething?

Most likely. Excess drooling and unusual fussiness are also signs

he's kind of fussy but he's been a drool monster for two months lol the biting just started.

@meagansimone

I don't know, but my little one does the same thing. She's also fussy, drooling more and sucking on her hands even when she's full.

Probably teething. I hear the first tooth takes the longest. Give baby something to chew on prior to feeding. My lo just started biting me at 2 nd a half months.

unfortunately he doesn't like to chew on his teething toys. he likes my phone though lol