Vine Takeover

Years ago I planted a pair of Bittersweet Vines bought from a local nursery. The are/were part of my American native Garden. 
I have a sneaky suspicion they are the Chinese Bittersweet variety. No  matter now. The berries are ripening n the female growing all over an old tree stump. And the male (shown here) has taken off climbing up a dead white pine tree. It must be 30 feet high by now and, alas, reaches over to the neighbours healthy Scotch pines. This action takes place right along our mutual property line. I worry about the strong possibility that the vine will start taking over & eventually kill the healthy pines not on my property.

I like letting the few old dead white pines stay as long as possible because  they benefit both insects and the birds who look for them (mostly woodpeckers) who enjoy the trees.
Another problem is with the berries. The birds do not seem to eat these foreign bittersweet berries. If they are allowed to fall anywhere new vines sprout and can take over.
I fear I have made a serious gardening mistake. The neighbour has a handy little portable chainsaw and that may take care of the problem if i point it out to her. She may want to take down the entire tree.
The blip shows the old vine attaching itself to the tree.  And, of course, my garden cat companion taking a moment for a quick wash up.