In my opinion no. You can be a cuck and do that but also not. Even though I enjoy my wife's creampie I consider myself a Stag and doing this does not make me a Cuckold. Sort of like sucking another guy off and swallowing his cum does not make me Gay or even Bi for that matter. Speaking for myself, there are sexual acts like eating creampie's or sucking cocks that I find exciting but for me these are very specific things. I see being a cuckold a role within the marriage or potentially a lifestyle but still a personal preference.