ok so my aunt just found she is pregnant but she cheated on my uncle she expects me to be happy for…

ok so my aunt just found she is pregnant but she cheated on my uncle she expects me to be happy for her and treat her like she's dying because her oldest is 16 and now she has one on the way. am I wrong to feel like she needs punched, my uncle is my father's brother just been with this girl for 10+ years