controlling mom???

Been with my man for a couple years now and it’s totally normal for us to spend time with his family christmas eve and christmas day and then do whatever with my family for the rest of the time, but i have gotten to the point where I get so anxious to even bring up to my mom that i’m doing this with his family first and then coming back. Its not like my family doesn’t like him or anything i guess they think I spend sooooo much of my time with him. Hes my best friend though? Just want some advice on how to just tell her this is what i’m doing, like i’m 20 years old and shouldn’t need permission to do stuff with each family for holidays. It isn’t like I completely ditch and don’t see my family the whole day or anything. The plan so far is lunch with his family christmas day and then dinner with my family but he now wants me to come to breakfast christmas eve with his step dads side and then go do whatever my family is doing. My mom already sajd “okay” for christmas day but now i’m steessed to even being up christmas eve.