Your former spouse being in a supportive relationship may be grounds for a modification of alimony. This can only happen if the court ordered the alimony in the first place or if you both reached a marital settlement agreement that left the alimony as modifiable. You should consult with an attorney on this issue to ensure that you qualify for a modification.
If you want to better understand what support payments may look like based on your financial situation, you can review how much will you pay in spousal support using our online calculator.