Now, you will see here multiple reasons why mate guarding is a turn off for women (it shows neediness, lack of abundance etc etc). But I would like to discuss one research I found regarding Ejaculate quality.

Basically this is the published research paper

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4176016/

which you can read if you want to, but I think the abstract explains it best

" In species where females mate with multiple males, the sperm from these males must compete to fertilise available ova. Sexual selection from sperm competition is expected to favor opposing adaptations in males that function either in the avoidance of sperm competition (by guarding females from rival males) or in the engagement in sperm competition (by increased expenditure on the ejaculate). The extent to which males may adjust the relative use of these opposing tactics has been relatively neglected. Where males can successfully avoid sperm competition from rivals, one might expect a decrease in their expenditure on tactics for the engagement in sperm competition and vice versa. In this study, we examine the relationship between mate guarding and ejaculate quality using humans as an empirical model. We found that men who performed fewer mate guarding behaviors produced higher quality ejaculates, having a greater concentration of sperm, a higher percentage of motile sperm and sperm that swam faster and less erratically. These effects were found independent of lifestyle factors or factors related to male quality. Our findings suggest that male expenditure on mate guarding and on the ejaculate may represent alternative routes to paternity assurance in humans. "

So, males that do not partake in mate guarding, have better semen.
Besides all the wheel spinning subconscious tactics, here's something engrained in our biology. And probably in women's biology too. Their primate brains already know this. Our primate brains already know this.

To rephrase the above, here's proof that if you Mate Guard, you are seen as weak.