Sensors for WHAT

Sounds like a problem many men would love to have.  I guess the only downside would be eventual repercussions:  losing your girlfriend, etc.  Since the sister is willing, and presumably of legal age, I can think of a few upsides, too. If you're willing to accept the negative outcomes, go for it.  If keeping your gf is important, discuss it with her and maybe include her in the fun.

Hi and welcome.  As my friend has already pointed out, this isn't a hookup site.  However I do hope you enjoy being a member of our community and look forward to your contributions.  

Hi and welcome Phil.  I hope you have a great time here. 

Next time be super desperate and show the desperation before letting go!