Sex is a crazy game. One must be comfortable playing in some teams since different teams have different playing styles.
Let your partner know you are uncomfortable with some activities on the bed.
Let your partner know what you love most, and do it well.
Truth be told, you can't go all round the football field on the first half of the game. Oral sex or head job...can happen only if you are super comfortable with yourself and your partner.
Imagine you guys just return from a walk and back in the hotel or bedroom, and he or she wants something in a hurry and starts pushing you down for a head-job? With a right mind, you can really think your partner has lost it.
But if both of you are really into each other, even at that hygiene is paradigm. Head-jobs are for ready individuals anything short from that, you guys should discuss and settle on what works for both of you...