The shooting took place at about 7:56 p.m. Wednesday at the home of woman's ex-boyfriend on Friendly Road near Tidwell.
Police said a woman and her new boyfriend showed up at her ex's home, which led to a fight.
The woman's new boyfriend pulled out a gun, shooting the ex-boyfriend, his mother, and his brother, according to police.
All three are expected to survive.
As for the woman and her boyfriend, they took off in a vehicle and remain on the run, police said.
An investigation is underway, but if you know any information on this incident, you are urged to contact Houston police.