Joe Alwyn “wouldn’t say” if he and Taylor Swift were engaged. The 31-year-old actor has been dating the ‘Love Story’ hitmaker for four years and he’s grown used to constant speculation about the state of their relationship, but insisted he’ll never confirm reports as to whether they are planning to tie the knot. Speaking to WSJ. magazine, he said: “If I had a pound for every time I think I’ve been told I’ve been engaged, then I’d have a lot of pound coins. “I mean, the truth is, if the answer was yes, I wouldn’t say, and if the answer was no, I wouldn’t say.” The ‘Conversation With Friends’ ac…