If / else if / else in while loop automatically prints else function

Question

Java beginner here. With the following code my else function automatically prints. So even before answering the question 'Do you want to buy the house with your partner? Type Yes / No' it's already throwing the else function out there.

//How much is the gross salary
    boolean partner;
    String partnerQuestion;
    double partnerSalary =0;
    System.out.print("Do you want to buy the house with your partner? Type Yes / No \n");
        while(true){
            partnerQuestion = sc.nextLine().trim().toLowerCase();
            if(partnerQuestion.equals("yes")){
                //how high is the loan                
                System.out.print("What is your partners´ anually gross salary? \n");
                partnerSalary = sc.nextDouble();
                partner = true;
                break;
            } 
            else if(partnerQuestion.equals("no")){
                partner = false;
                break;
            }  
            else{
                System.out.print("I did not understand you. Please try again.");
            }
        }

To give a good picture my if / else inside this while loop, does work.

boolean timeTF;
    double term;
    System.out.print("For how many years should the mortgage run? Choose between 10/15/20/25/30 \n");
        while(true){
            term = sc.nextDouble();
            if(term != 10 && term != 15 && term != 20 && term != 25 && term != 30){
                System.out.print("Please type 10/15/20/25/30, other values are not valid \n");
                timeTF = true;   
            } 
            else{  
                timeTF = false;
                break;
            }
        }

So my question is, what am I missing? Thanks in advance.