My 9-year-old son wore makeup to school. What should I do?

We have 2 children: a 9-year old boy and a 4-year old girl. Our son has always been precocious, intelligent, and sensitive. He's a very cute and charming kid, and people love him. However, he's always been a "softer" kid, and has sometimes dealt with bullying from people who call him girly, skinny, gay, etc. My husband was raised in a strict evangelical family in the rural midwest and has very traditional views on masculinity, and though he loves our son to death, this has been a point of contention in their relationship. He's always after my son to get interested in more traditionally "boyish" things like sports, hunting, cars, etc. He sometimes gets a little irritated when my son instead prefers to read books at home or play around with his little sister and her dolls.Recently I caught my son trying on some of my makeup - just some blush, mascara, lipstick, etc. It was a little surprising to me, but my first thought was that my son had actually done a pretty good job at applying it, LOL. I asked him what he was doing and he got really embarrassed, said he was just messing around with it and wouldn't do it again. I said okay and didn't press the issue further, since I felt he was uncomfortable.However, a few weeks later I found out that he had gone to school with a small, but noticeable amount of makeup. He sometimes runs directly to the carpool in the morning and I don't notice him. We only found out from the parent of a friend, who ended up calling my husband about it after school. Apparently my son had done the same thing as before, used a little bit of blush and lipstick, enough for anyone to obviously tell. My husband freaked out over this. While I wasn't home, he confronted my son, who said he'd just tried it out because he liked the way it looked. Apparently they got into a huge fight, and my husband ended up yelling at my son, spanking him, and sending him to his room.I only found out about all this once I got back from work. I couldn't believe my husband had reacted this way. He's never been violent with the kids before. I comforted and hugged my son, who was still crying. I told him everything was okay. He's been terrified of his dad ever since. I asked my husband what the hell he was thinking, but he said he was just trying to do the right thing for our son, and if he kept on the way he was going he would be bullied and ostracized by the other kids. He told me to keep the makeup away from our son and to start forcing him into more "masculine" activities and extracurriculars.I'm at a loss for what to do here. I think what my husband did is unacceptable, and I don't know how to deal with this going forward. What should I tell my son? How should they mend their relationship? I want my son to be able to express himself, but I don't want him to be bullied or made fun of. via /r/Parenting http://bit.ly/2GTGPGM