Josh Allen and Hailee Steinfeld are now apparently so serious ... one of the NFL star's closest teammates just said he believes the quarterback is "in love" with the actress.
Buffalo Bills left tackle Dion Dawkins broke it all down while appearing on Kay Adams' "Up And Adams" show on Tuesday alongside Taylor Lewan.
The 29-year-old offensive lineman -- who's great pals with Allen -- was talking about how the signal-caller famously split his pants in Paris last week .