Spain is one of the most enlightened countries out there where gay-lesbian issues and rights are concerned. Homosexual couples can marry and have families here, and in any city you will see many same-sex couples and families holding hands, being affectionate, etc. I don´t know where you are from, but you may feel much more free here to express your affection than you do at home.
At least in the cities.
Discrimination against couples by hoteliers and other for-profit businesses is illegal, and besides, they really need the business these days. As for pilgrim albergues, sleeping together is a practical impossibility, although some very passionate (and sometimes thoughtless) couples still have a go sometimes!
Out in the provinces, things progress more slowly. People still make jokes or roll their eyes, but only among themselves. I have lived in rural Spain for three years, and I have never seen any kind of outright nastiness aimed at same-sex couples or openly homosexual individuals. Still, you are traveling through some very conservative areas. You will do well to practice discretion.
I do not think you will have any problem with Spaniards.
Your fellow pilgrims may present other challenges, however. I´m sure it´s nothing you´ve not encountered before, and have dealt with commendably.
Reb.