Search Results: signs a guy likes you laugh

So this is a pretty long story. The reason I need this much advice is because I'm a chronic overthinker and have gotten hurt by misinterpreting "signs" I thought I was certain about.

My [M21] friend [F25] and I are mutual friends of my cousin [F30]. Three of us have been hanging out every weekend for the past four months. Girl has been to a family wedding, events, parties, etc. The cousin has told other cousins (who want the girl and I to date) that she doesn't want to lose a friend, but it's more that she's 30, hasn't had a boyfriend in years, plays around with guys, and just wants a sidekick to go through it with.

The girl started being very flirty at end of May. She has:
- Told me I have pretty eyes
- Major physical contact: grabbing my hand, resting her head on my shoulder (especially when I make her laugh), hugged me from behind, rubbed her whole body up against me
- Jokes or "jokes" with my parents being her in-laws
- Sent me a picture of a hot bathing suit for opinion on color
- Sent me a private snap of her in a sports bra and leggings before hitting the gym. She never private Snaps me.
- Has said "should we kiss?" a few times. Joking, but the last time was more subtle and serious.

Things didn't get heated until I started giving serious vibes back. The girl has said to a mutual friend, who's sort of my wingman, that I'm the "type of guy you marry, and take it slow with." I feel the same way about her. I don't to start something serious if someone else sees it as a game or just me being spiteful.

The problem is: some weeks the vibes are incredibly flirty and almost romantic, other weeks we're basically just friends. I can't really gauge what she wants and I want to make a move and escalate things but don't want to make her uncomfortable if she's not feeling it. Am I being "reeled in?"

Also, should I talk to my cousin first and state my intentions clearly, or should I wait until things sort of boil over, ending up in a serious moment or conversation?

We had known each other 3 years but I was never that close to her before, she was just in the circle of friends and I occasionally spoke to her. 6 months ago she acted like this - In a group, she talks to me over any other guy and sometimes seems like she’s following me even if I’m taking to others. She tries to butt in the conversation too. If I ask if she wants to do something she won’t say no unless she’s thinking of seeing her parents or siblings then. If she’s not keen on something she’ll say so but might do it anyway. She laughs at my jokes and if I make prolonged eye contact, she’ll maintain it for 5 seconds then look away. She asks me lots of questions and tells me everything too.

She changed a few months ago though. And I don’t understand what happened.