my suggestion is not to make declarative statements...i would never fall for someone else, i don't see myself falling in love with another man.... i did that and then had to fight for a number of years to get my partner to let me be with someone of the opposite sex. i didn't think i would ever want to be with another man, because we were in the flush of new love and i agreed that i would only find another relationship with another woman. it took me a few years to realize i was limiting myself, i wasn't a homosexual with an aberration relationship with this man, i was a bi-sexual who definitely likes other men. and it took even more years to get him to agree to change the parameters. so, just be happy with the people you are with and be honest that you don't know what the future will bring, or who, and flexibility is the key. titles are arbitrary.
crab-lion: 42 y/o bi woman domestic partner w/lion
lion: 39 male hetero domestic partner w/crab-lion
twin: bi woman lion's girlfriend/almost lover
d: hetero woman lion's long distance girlfriend