Hispanic/Latinx young adults remain significantly underrepresented in science, technology, engineering, and mathematics (STEM) fields, yet the role families play in these young adults' trajectories in STEM is still underexamined. The purpose of this study was to examine the relational supports and constraints that Hispanic/Latinx college students in STEM majors experienced with their parents as they moved through college and transitioned into their first year of graduate school or full-time employment. Two rounds of interviews were conducted with 18 Hispanic/Latinx young adults who were part of an undergraduate STEM program at a Hispanic-majority university. Most of the study participants reported benefiting from immense emotional support from their parents; however, this emotional support was often simultaneously coupled with home-school value conflicts and a dynamic we call "conversational constraints." Results from this study point to important interventions involving family that might improve the rates of participation of Hispanic/Latinx students from a range of socioeconomic backgrounds in STEM fields.