How can I express the fact that the reason why I wore pants has been the same?

Since the start of the latest lockdowns, I haven’t been wearing pants often. The only times when I wear it have been when I meet with a particular friend of mine. Now, I want to express the fact that this particular friend of mine has been the only reason why I wore pants. However, I’m having a bit of trouble:

If I say

S/he has been the only reason I have been wearing since the start of the latest lockdown.

The reader might understand as if I have been wearing pants for several months now. Even though the act of wearing pants has been done several times for short time periods, the reason why such an act has been the same. So, when I say "since …", the time phrase should modify the noun reason and not wear.

How can I express what I want to say, just like in the above example, in a single sentence without causing possible confusion?