My personal experience being a kid in a broken home (it is what I call my child life, don't correct it even if you feel the need) is that it should be up to the kid as soon as they express their opinions. Even if it hurts a grown ups feelings.
The work around to this is to do shared visits at a park until the kid is comfortable being alone with the other adult. If the adult who is not being chosen feels shunned? They should. And they should self evaluate 'why' they are being shunned and put in that extra effort.
I am not saying your DP is being shunned, but there would be reasons why your DSS is vocalizing this opinion, and it very well could just be an immature reaction to your DP being deployed. But DSS is 17, he has the right to be immature at times, it is a part of growing up and learning how to react to situations.
More from personal experience when I became an 'adult' legally I stopped visiting my dad very often. I kick myself in the ace every day because my dad died when i was about 22ish and now I look back at all the missed opportunities. No one at the time could have explained to me why it was important, and my dad still made the effort and when he did we hung out, but I know I didn't do everything I could have on my end. Anyways...
To answer your question if a child feels 'off' about EOW visits, then it should be respected in my opinion, and the parent who is being put off should be required to go the extra distance to meet the kid on comfortable terms. Meeting at parks, the mall, arcades, swimming pools, lakes.
Plan outings and have them show up, your DSS is a little old, and it really should be up to him how to handle end of week visits, but the thought process is still the same. DP plan an outting and invite him along, if he doesnt want to go? He won't, if he does? He will.