Is this a good idea? i'm about to spend alot of money, so advice would be useful!?

here's the thing. my girl and i have been talking about a trip to mexico for christmas. HOWEVER, her ex is having some health issues and some difficulty getting over her. we have taken a break so she can spend some time with him. This is not what either of us want. she feels sorry for him, and i agree he does need some extra support right now. i can't allow this to continue forever, she's in love with ME afterall. so i'm arranging the vacation tomorrow thru a travel agent. i will present the package as a gift that i will probably just leave on her doorstep with a note asking her to join me. if she says yes, we'll celebrate christmas on the beach as planned, but i'll redirect our flight home to NYC for new years celebration, something else we've dreamed about. this is where i intend to propose to her. i already have the tiffany engagement ring, it's been burning a hole in my pocket but i'm waiting for the right moment. i'm trying to create the right moment and some good memories. am i being too forceful, or am i right to step in and get my girl back this way?