Selecting one specific data row (required), and 3 others (specific data row must be included) - postgresql

Question

I need to select a specific row and 2 other rows that is not that specific row (a total of 3). The specific row must always be included in the 3 results. How should I go about it? I think it can be done with a UNION ALL, but do I have another choice? Thanks all! :)
Here are my scripts to create the sample tables:
create table users (
user_id serial primary key,
user_name varchar(20) not null
);
create table result_table1 (
result_id serial primary key,
user_id int4 references users(user_id),
result_1 int4 not null
);
create table result_table2 (
result_id serial primary key,
user_id int4 references users(user_id),
result_2 int4 not null
);
insert into users (user_name) values ('Kevin'),('John'),('Batman'),('Someguy');
insert into result_table1 (user_id, result_1) values (1, 20),(2, 40),(3, 70),(4, 42);
insert into result_table2 (user_id, result_2) values (1, 4),(2, 3),(3, 7),(4, 5);
Here is my UNION query:
SELECT result_table1.user_id,
result_1,
result_2
FROM result_table1
INNER JOIN (
SELECT user_id
FROM users
) users
ON users.user_id = result_table1.user_id
INNER JOIN (
SELECT result_table2.user_id,
result_2
FROM result_table2
) result_table2
ON result_table2.user_id = result_table1.user_id
WHERE users.user_id = 1
UNION ALL
SELECT result_table1.user_id,
result_1,
result_2
FROM result_table1
INNER JOIN (
SELECT user_id
FROM users
) users
ON users.user_id = result_table1.user_id
INNER JOIN (
SELECT result_table2.user_id,
result_2
FROM result_table2
) result_table2
ON result_table2.user_id = result_table1.user_id
WHERE users.user_id != 1
LIMIT 3;
Are there any options other than a UNION? The query works and does what I want for now, but will it always include user_id = 1 if I had a larger set of rows (assume that user_id = 1 will always be there)? :(
Thank you all! :)