Holiday Close with a Friend

I'm on a 10 day holiday at the seaside and there is this HB6 friend of mine. I know she had things for me but is afraid of telling me. She also makes it so obvious that anyone watching from outside can get it, like she always caresses my cheek, strokes my hair when she is making a joke, brushes her tits against my back when we are looking at something away, randomly squeezes my shoulder and arm muscles.

Today, we were on a bus trip and she asked me to buy her some crisps. I asked her "In exchange of what?" and she said "I don't have money but I can give a kiss." I replied "Well, the quality of the crisps you get depends on the kiss you give, right?" and she says "Then I should give a French kiss to get the best!". Then she put her hand on my leg, just next to my crotch. That moment, I had the best opportunity to K close or even F close if we had not been on a bus with people around and most importantly, her bigger brother and family members sitting at the seats in front of us.

Here comes the main problem. Although she is 23, her brother still follows after her everywhere she goes and her family is extremely cautious about her relations with boys. (Maybe she had some disturbing experience earlier that I don't know.) I am also like a part of the family and every member of the family knows me and tells me how well-behaved I am. They even leave her with me alone knowing that I am the safe guy.

Now, I admit that I am being a bad guy but getting all the hints that I wrote above, I would like to f-close this girl before the holiday ends and I would like to hear some advice on how to do it with all these conditions. I also do not want a LTR, only a holiday fling and I do not know how I will explain it to her if she asks me about it after we kiss. Help me guys!