Before you make plans to eliminate boyfriend maybe you'd like to tell us in what state boyfriend and wife reside. It really isn't all that difficult.
Why the state? Because if a community property state (like mine) and the premiums are derived from community property, boyfriend's widowed wife would be entitled to one-half of the proceeds. What rights a widow in a common law state might have I cannot say and I ain't about to look.
But I'm with adjax because I'll wager that you have never seen a designation of beneficiary nor recognize one if you did see one, MUCH LESS have access to the records of the insurer. And that boyfriend is stringing you along with this enticing carrot until he finds a more appealing/younger concubine.