For some reason, ex-Baylor football player Tre'Von Armstead was all smiles after his arrest Monday morning ... despite allegedly roughing up a woman and kicking out a police car window.
TMZ Sports broke the story ... the 22-year-old former Baylor tight end was arrested in front of The Cromwell hotel around 4AM after cops say they watched him push a female on the street.
During the arrest, 6'6", 280 pound Armstead allegedly kicked out the back window of a police squad car.
We've confirmed Armstead is out of police custody -- but he's still in all sorts of hot water having been booked for battery domestic violence, resisting arrest and damaging a police car.