Husband buying a house

My husband decided he wants to buy a house because his family is losing theirs and doesnt want them on the street even though I offered to let them stay with us rent free until they can figure their own life out but my husband was pissed off because i gave his family a timeline. He also states that this is his back up plan should things not work out with us. This makes me even more mad because the other day his father accused me of cheating with fake messages. Am I over reacting by not being okay with this. Or should I just go with the flow.