Hello sunnysarah. What a strange image you have conjured up in my mind.
I can't decide how far apart these two poor trees might be, how they came to be there and what the original plan was for them. Fir trees grow to a tremendous height so you, or someone in the future, is definitely going to have to bite the bullet eventually. Unless they are halfway up a mountainside and have plenty of scope for growth. In which case, why hide them?
If they are a few feet apart maybe they would be able to support a hammock in a few years time?
I can't really see a clematis forming an attractive partnership with two fir trees, but my imagination isn't the best. Why grow clematis - to disguise the trees? They won't put up with that for very long and then you will have three unhappy plants to deal with instead of two!
Are they old Christmas trees? I inherited a garden once with a selection of ever-diminishing sizes of trees from Christmasses past. I dug them up, drove to a quiet spot and planted them au naturel. No idea how they got on. Probably got dug up the following December by someone keen to have a free yule log!
Sometimes one just has to be hard hearted, I'm afraid.