Why does my husband insist on goin on grateful dead tour?

Were a month a away from another baby...been together 6 yrs..now that he's intouch with his old friends he wants to leave me with a 4 yr old and a 1 month old to go on tour!...now its no place for children so obviously I can't go...ill be stuck at home with the kids WORKIng to make morguage payments..while he's gone for weeks on end partying and doing drugs..he says he will be faithful..but I know he won't....should I just call it quits?...I'm really not comfortable with it I told him this..he dosnet care, he thinks I'm overreacting