Would you be sad if your husband didn't try to defend you to his mother?

For starters I know this is 100% my fault. Me and my husband are trying to see if we can save our marriage. I had an affair with an ex boyfriend. I know it was wrong. Between us working and being parents it just felt like the spark left our marriage. When my ex hit me up it reminded me of being young and the excitement in a relationship and I feel awful. My ex best friend is the one who kept convincing me to go for it and when I did SHE told my husband. We have 5 kids which is why just getting a divorce is hard and my husband said he may want to work it out, he just needs time. His parents know about the affair and me and his mom didn't get along a whole lot anyway but she absolutely hates me now. What happened is I heard ad conversation where his cousin was telling them how his wife keeps leaving food out and he laughed and said "I would be pissed if mine wasted food like that." My MIL told my husband he has no room to talk because he wins at having a crap wife. My husband says "Mine doesn't waste food." And my MIL said "No. She just wastes feelings and families." I heard this and my husband said nothing.... I guess I wish he told her "It's our business" or "We are trying to work it out." Just something to his mom ya know...