Is this girl hitting on my boyfriend?

About a week ago our new roommate moved in; she is taking a summer class so she'll only be here for five weeks. I'm the one that invited her to live with us because she had no other place to stay. The very first day she was here when my boyfriend left after visiting me she said, "Chrissy, your boyfriend is SO adorable!" I thanked her for the compliment but she kept gushing about how hot she thinks he is. I didn't take this offensively and went on my way. Two nights ago she came to me and asked if she could talk to my boyfriend (whose name is Matt) about his tattoo. She said she wanted to get one and had some questions for him; again, I thought nothing of this and asked him to come over so they could talk. All three of us along with one of my other roommates were out in the living room while she was asking him questions. The first thing she said was, "Can I see your tattoo?" I wondered how this would help solve any of the other questions she asked him, like how long it took to heal and how much it would cost. Instead of taking his shirt off my boyfriend barely pulled his collar to the side so that you could see a glimpse of his tattoo. Her face looked disappointed but she said it was an awesome tattoo and kept asking him questions. At that point a little light bulb went off in my mind - I didn't say anything to my boyfriend because I didn't want him to think I was overreacting. The next morning she left to go home for the day so she could get the tattoo; upon her arrival back at the apartment she immediately started bragging about her tattoo. I told her it was really pretty and asked if she did okay driving back and such. She said, "Yeah it was fine. Do you think Matt wants to see it?!" Being naive as I am, at this point I should have said, "Why the hell would MY boyfriend want to see YOUR tattoo?" But I didn't. We went over to my boyfriend's apartment (he lives in the same building) and she said, "What do you think?" asking only my boyfriend and none of his roommates. As I sat down I looked up at her and noticed that the bikini top she was wearing (she wore it in order to get the tattoo on her side/rib cage) was barely covering the boob above her tattoo. I almost lost it - about the bottom 1/3 of her boob was hanging out and she was flaunting it to my boyfriend! I called my mom and tried to explain the situation to her as unbiased as possible so I could get her opinion. She immediately told me I need to set my new roommate straight because her actions were unnecessary and inappropriate. What I want to know is if I'm overreacting or if this girl is after my boyfriend.